1. Field of the Invention
The present invention relates generally to ratchet wrenches and, more particularly, to ratchet wrenches having adjustable jaws.
2. Description of the Prior Art
Ratchet wrenches are well known in the art and most commonly include an assembly which includes a handle, a ratchet mechanism attached to the handle, and an adaptor for receiving a socket. A set of different size sockets is provided to attach to the adaptor on the handle-ratchet assembly. Bolt heads, for which sockets are made to fit, common in a variety of sizes. Moreover, in one convention, the bolt heads and the sockets are dimensioned according to the Metric system. In another convention, the bolt heads and the sockets are dimensioned according to the English system. Although a single handle-ratchet assembly may be used with a wide variety of socket sizes, it would be desirable if an adjustable ratchet wrench could be provided which would avoid the need for a wide variety of differently sized sockets.
Throughout the years, a number of innovations have been developed relating to adjustable ratchet wrenches, and the following U.S. patents are representative of some of those innovations: U.S. Pat. Nos. 3,803,954; 4,112,792; 5,040,439; 5,090,273; and 5,095,782.
More specifically, U.S. Pat. Nos. 3,803,954 and 5,095,782 disclose adjustable ratchet wrenches which have a handle that pivots with respect to the jaws of the wrench. The pivoting action serves two purposes. One purpose is to tighten the wrench jaws on a nut or bolt. The other purpose is to turn the nut or bolt. In using this type of adjustable ratchet wrench, a relatively large portion of the motion of the handle in using the wrench is consumed by tightening the jaws of the wrench on the nut or bolt. Therefore, a reduced portion of the motion of the handle is utilized for the main function of the wrench which is turning the nut or bolt. In this respect, it would be desirable if an adjustable ratchet wrench device were provided in which substantially all of the motion of the handle of the device were utilized in turning the nut or bolt.
U.S. Pat. No. 4,112,792 discloses an adjustable ratchet wrench which has a closed box end. A disadvantage of the adjustable ratchet wrench in this patent is that the end of the wrench is closed. In many instances, an open-ended wrench is needed for a variety of applications, and a closed ended wrench will simply not work. In this respect, it would be desirable if an adjustable ratchet wrench device were provided which included an open-ended wrench.
U.S. Pat. No. 5,040,439 discloses an adjustable wrench that employs a chain for tightening around a pipe. The chain is employed to exert clamping pressure on the pipe to assure a secure grip. However, the chain is a bulky item. In this respect, it would be desirable if an adjustable ratchet wrench device were provided which did not employ a chain for gripping a pipe.
U.S. Pat. No. 5,090,273 discloses an adjustable ratchet wrench which includes three sliding jaws which are opened and closed by a cam disk. For purposes of simplicity, it would be desirable if an adjustable ratchet wrench were provided that has only one adjustable jaw.
Still other features would be desirable in an adjustable ratchet wrench apparatus. Locking pliers are well known in the art. With a locking pliers, a clamping force is exerted on an object by the jaws of the pliers, and the jaws are locked into a clamping force exerting mode. None of the prior art devices discussed hereinabove have a locking-plier feature, and it would be desirable if an adjustable ratchet wrench apparatus were provided which included a mechanism for locking the jaws of the adjustable ratchet wrench apparatus onto an object.
A simple ratchet mechanism works to ratchet in one direction. To provide a ratcheting action in two directions, that is both clockwise and counterclockwise, two ratchets must be provided, one for each direction. For purposes of simplicity, it would be desirable if a unidirectional ratcheting mechanism were provided in an adjustable ratchet wrench apparatus. With a unidirectional ratcheting mechanism, the adjustable ratchet wrench apparatus would be flipped over to reverse the operative direction of the unidirectional ratcheting mechanism. More specifically, a ratcheting mechanism that ratchets in a clockwise manner will ratchet in a counterclockwise manner when flipped over.
Thus, while the foregoing body of prior art indicates it to be well known to use adjustable ratchet wrenches, the prior art described above does not teach or suggest an adjustable ratchet wrench apparatus which has the following combination of desirable features: (1) avoids the need for a wide variety of differently sized sockets; (2) employs substantially all of the motion of the handle of the device in turning a nut or bolt; (3) includes an open-ended wrench; (4) does not employ a chain for gripping a pipe; (5) can have only one adjustable jaw: (6) can include a mechanism for locking the jaws of the adjustable ratchet wrench apparatus onto an object; and (7) provides a unidirectional ratcheting mechanism. The foregoing desired characteristics are provided by the unique adjustable ratchet wrench apparatus of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.